A hard disk drive (HDD) stores information by digitally encoding the data on rapidly rotating platters with magnetic surfaces. The HDD includes read/write heads and a servo head that are mounted on the end of a rotary arm actuator. When the disk unit is turned off, these heads are loaded onto plastic “ramps” near the outer disk edge. When the disk unit is turned on and the drive motor spins the disk platters to a high speed, air pressure, and the aerodynamic characteristics of the head design, cause an air-bearing to form which causes the heads to take off from the disk surface and “fly.” When the disk heads are flying, they are unloaded from the ramps and moved over the area on the disk platters containing data. The head assemblies are designed such that between the air-bearing force that tries to lift the heads and the spring force that causes them to land on power-off, they fly at approximately 19 microinches (0.48 microns) above the disk surface.
The interior of the cavity is designed such that the rotation of the disk platters causes high- and low-pressure areas. The resulting circulating air flow is directed through a 0.3 micron absolute filter within the sealed cavity. Thus, the air within the cavity is being continually filtered. Another 0.3 micron absolute filter on the bottom cover is used to allow the cavity pressure to equalize with the outside ambient pressure.
If a particle of dirt passes under a flying head it can disrupt the air bearing and cause the head to “crash” onto the surface of the spinning disk platter. A head crash will generally cause a catastrophic failure of the HDD. Therefore it is necessary that the heads and disks be sealed in a clean cavity free of particles. To achieve this, a HDD is constructed with a head-disk assembly (HDA) that is sealed with a cover in a clean-room to provide a clean cavity within the HDD that safely houses the heads and disk platters. The HDA is cleaned before being sealed to remove particles, particularly those larger than 0.5 microns in size. The cleaning may be done by a manual vacuuming process, which is time consuming and inconsistent in terms of particle removal.
It would be desirable to provide a cleaning machine to automate the HDA cleaning process and improve the removal of particles.